Cellulose derivative composition



Patented Sept. 4, 1934 UNITED STA 1,972,091 CELLULOSE DERIVATIVE COMPOSITION George De Witt -Grav Lawson, Wilmington,

du Pont de Nemours & Company,

es and Walter Eastby Del., assignors to E. I. Wilmington,

DeL, a corporation of Delaware No Drawing. Application June 10, 1931, Serial No. 543,387

9 Claims.

This invention relates to cellulose derivative compositions and, more particularly, to such compositions including, as plasticizers therefor, organic polycarboxylic acid esters containing an esterified higher alkyl group.

An object of the present invention is to provide cellulose derivative compositions of improved water resistance. A further object is to provide cellulose derivative compositions which are substantially permanently flexible, and having improved durability. Other objects will be apparent from the description of the invention hereinafter given.

The above objects are accomplished according to the present invention by the use of esters of organic polycarboxylic acids, at least one acid hydrogen atom of which has been replaced by a normal saturated aliphatic radical containing from 6-15 carbon atoms, as a plasticizer for the cellulose derivative.

The invention contemplates within its scope the use of esters of any of the organic polycarboxylic acids, whether belonging to the aromatic or aliphatic series. One or more of the carboxylic hydrogen atoms is replaced by a normal saturated aliphatic radical containing from 6-15 carbon atoms corresponding to the following list of alcohols:

0 n-hexyl CsHuOH n-heptyl C7H15OH n-octyl CsH1'z0H n-nonyl C9H19OH n-decyl C1oH21OH 5 n-undecyl CnHzaol-l 1all1Iy1 C12H25OH n-tridecyl C13H2'IOH myristyl C14H29OH n-pentadecyl C15H31OH The esters may contain only one of the above listed allgyl groups and may contain a free carboxylic acid group. Alternatively, an ester containing one normal saturated aliphatic group having 6-15 carbon atoms, may have another carboxylic acid group esterified with any other alcohol. The invention also includes the use of esters of polycarboxylic acids in which more than one acid hydrogen is replaced with a normal saturated aliphatic group having from 6-15 carbon atoms. Accordingly.,the invention .includes the use of neutral esters of organic polycarboxylic acids in which all of the carboxylic acid groups are esterified, such esters containing one or more of the alkyl groups listed above.

'55 The polycarboxylic acids which may be esterifled to yield the esters included within the present invention may contain two or more carboxylic acid groups. The following organic acids are named as typical of those which may be used:- orthophthalic, terephthalic, oxalic, succinic, adipic, maleic, fumaric, tartaric, malic, citric, quinolinic, trimesic, pyromellitic, naphthalic, naphthalene, tetracarboxylic, tricarballylic, hexahydrophthalic, hydro'xy phthalic, uvitic, tetrachlorophthalic, sebacic, itaconic, and pimelic.

In our copending applicationexecutedof even date herewith, Serial No. 543,386, thgesters included within the present invention are disclosed, as Well as their method of preparation. These esters are preferably made by bringing together the desired alcohols and acids (or where the anhydride of the polycarboxylic acid is available it may be used in lieu of the acid) and then heating the mixture, preferably at temperatures above 100 C. so that the water produced by the esterification will boil off and thus permit the reaction to go to completion. The removal of this water may be assisted by adding to the esterification mixture a carrier liquid, such as benzene 'or toluene, which will distill out with the water at a temperature below 100 C., in which case the esterification may be carried on at a lower tem-' perature than would otherwise be used. An inert gas, such as carbon dioxide, may be continuously passed through the reacting mixture to accom-' plish the same purpose, namely, to facilitate the removal of water.

The following examples are given to illustrate typical molding and lacquer cellulose derivative compositions employing the above described esters as plasticizers for the cellulose derivative Momma CoMPosrrions Tricresyl phosphate 15 Example 3 Parts Cellulose acetate 100 Dilauryl phthalate 30 Example 4 Parts Cellulose acetate Dilauryl phthal 20 Triacetin 15 Example 5 Parts Cellulosev nitrate 100 Lauryl butyl phthalate 35 LACQUEli Courosrrrons Example 6 Parts Cellulose nitrate 12 Damar--- 3 Lauryl butyl adipate 4 Castor 011 y .2. 6 Solvent 24 Example 7 Parts Benzyl cellulose 4 Dilauryl succinate 1 Hexyl caproate 1 Solvent. -1 24 Example 8 Parts Benzyl cellulose I 4 Damar' 1 Dioctyl adipate 1 Solvent 24 Example 9 Parts Cellulose nitrate 12. 0 Damar 3. 0 Dilauryl adipate 4. 0 Pigment 16. 3 Castor oil I 2. 6 Solvent 161.6

In the above examples, showing lacquer compositions, any suitable solvent, such as a mixture of alcohols and esters and hydrocarbons, may be used, as will be understood by those skilled in the art. Solvents may also be used with the molding compositions, if desired. As will also be obvious to those skilledin the art, various gums, natural or synthetic resins, such as polyhydric alcoholpolybasic acid or phenol-formaldehyde resins, pigments, and the like, may be included in these compositions.

Not only dicarboxylic acid esters may be used, as shown in the above compositions, but also tricarboxylic, or higher polycarboxylic acid esters may be used, such as trilauryl citrate. The cellulose derivative compositions containing the esters described above may be used either as lacquers or as molding compositions, as shown in the above examples, or asdopes for usein the preparation of coated fabrics. In the case of the lacquers and the dopes, they may be applied by spraying, brushing, flowing, spreading under a doctor knife, or by other suitable methods of application. When used as moldingcompositions they can be molded according to the known methods of the plastic a'rt. They also can be'pressed into cakes and sheeted to form comparatively thin films which find use as strengthening layers for safety glass and in other applications where materials of this sort are regularly used.

The cellulose derivative compositions, which may include esters or ethers, are characterized by the fact that they are exceptionally resistant to water, since the plasticizers used in these compositions are all esters of higher aliphatic alcohols. having substantial water resistance. The compositions are exceptionally durable and substantially permanently flexible, due to the use of the I herein described esters as plasticizers. These esters have higher molecular weightsthan the 95 commonly used plasticizers and, consequently, have higher boiling points and lower vapor pressures, properties which insure substantially permanent retention of the plasticizer in the ,cellulose derivative composition, and hence a flexible 10D and durable product. The esters are satisfactorily compatible with cellulose derivatives and give compositions of exceptionally favorable properties. i

As many apparently widely diiferent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that'we do not limit ourselves to the specific embodiments thereof except as defined in the appended claims.

We claim:

1. A composition of matter comprising a cellulose derivative and a lauryl phthalate.

2. A composition of matter comprising a cellulose derivative and dilauryl phthalate.

3. A composition. ofmatter comprising a cellulose derivative and a lauryl adipate.

4. A composition of matter comprising a cellulose derivative and dilauryl adipate.

5. A composition of matter comprising a cellulose derivative and a lauryl ester of an organic polycarboxylic acid.

6. A composition of matter comprising a cellulose derivative and a lauryl ester of an organic dicarboxylic acid. a

7. A composition of matter comprising a cellulose derivative and a di-lauryl ester of an organic dicarboxylic acid.

8. A composition of matter comprising a cellulose derivative and a lauryl alkyl phthalate.

9. A composition of matter comprising a cellulose derivative and lauryl butyl phthalate.

GEORGE DE WI'I'I' GRAVES. WALTER EAS'I'BY LAWSON. 

